Sharpless and co-workers first introduced the concept of “click chemistry”,[1] employing powerful and selective reactions for the efficient synthesis of interesting compounds and materials through heteroaromatic links, e.g., Huisgen 1,3-dipolar cycloaddition of azides and alkynes.[2] This modular process is reliable, widely applicable, of high yield, and requires only simple reaction and purification conditions. It does not involve reagents that are difficult to handle, and is stable towards strong bases.[3]
Recently, applications of “click chemistry” were reported in the synthesis of chemically and biologically useful materials.[4,5] However, the development of heterogenized catalysts has seemingly produced the most significant impact on the chemical and pharmaceutical industries.[6,7] Although attempts to immobilise homogeneous catalytic complexes (not via click chemistry) on various supports have been reported[7A], these have not always generated sufficiently effective heterogenized catalysts for industrial applications. Immobilised catalysts (also referred to herein as heterogenised catalysts) can offer a number of advantages, such as ease of catalyst recovery and products isolation, reduced production costs, and decreased catalyst contamination of products, etc.[8,9] Such systems are of great interest given the growing demands of inexpensive green chemistry.[32]